English

Noncommutative ergodic theory of higher rank lattices

Operator Algebras 2025-07-17 v1 Dynamical Systems Group Theory Representation Theory

Abstract

We survey recent results regarding the study of dynamical properties of the space of positive definite functions and characters of higher rank lattices. These results have several applications to ergodic theory, topological dynamics, unitary representation theory and operator algebras. The key novelty in our work is a dynamical dichotomy theorem for equivariant faithful normal unital completely positive maps between noncommutative von Neumann algebras and the space of bounded measurable functions defined on the Poisson boundary of semisimple Lie groups.

Keywords

Cite

@article{arxiv.2110.07708,
  title  = {Noncommutative ergodic theory of higher rank lattices},
  author = {Cyril Houdayer},
  journal= {arXiv preprint arXiv:2110.07708},
  year   = {2025}
}

Comments

22 pages; Prepared for the Proceedings of the ICM 2022